Apparatus and method for limiting movement of a work machine

ABSTRACT

A work machine having a traveling body, a moveable structure coupled to the traveling body, a sensor operable to generate a sensory signal, and a controller. The controller is in communication with the sensor. The controller including a processor and a memory having a position control algorithm stored thereon. The processor is operable to execute the position control algorithm to receive a boundary command establishing a defined boundary; receive a sensory signal from the sensor related to the movement of the movable structure; determine a position of the movable structure relative to the traveling body; and limit movement of one of the ground-engaging mechanism of the traveling body or the actuator of the moveable structure as the traveling body moves along the travel path when the position of the movable structure is within an allowable distance from the defined boundary.

CROSS-REFERENCE TO RELATED APPLICATIONS

N/A

FIELD OF THE DISCLOSURE

The present disclosure relates to an apparatus and method for a work machine.

BACKGROUND

Operators actively monitor work performed at a work site during operation. However, the rough environment and long hours can lead to operator fatigue. This can lead to inconsistencies in for example, digging a straight edge, if the operator fails to remain vigilant. Under particularly adverse situations, machine downtime may occur to rectify any inaccuracies. The downtime may accumulate with time and become substantial. The heavy reliance on experienced operators for worksite may reduce efficiencies because of potential challenges to find personnel. With multiple controls to move, for example, a boom arm on an excavator may not be intuitive for a novice operator and would require several man hours of training. Therein lies potential for reducing this reliance on the operator by improving the work machine and its method of operation. This is especially relevant during work machine travel where work machines may need to move about various worksites.

SUMMARY

This summary is provided to introduce a selection of concepts that are further described below in the detailed description and accompanying drawings. This summary is not intended to identify key or essential features of the appended claims, nor is it intended to be used as an aid in determining the scope of the appended claims.

The present disclosure includes a work machine comprising a traveling body, a moveable structure, a sensor, and a controller. The traveling body includes a ground-engaging mechanism controllable to move the traveling body along a travel path relative to the ground surface. The moveable structure is coupled to the traveling body and has an actuator controllable to move the moveable structure relative to the traveling body. The sensor is operable to generate a sensory signal. The controller is in communication with the sensor wherein the controller includes a processor and a memory having a position control algorithm stored thereon. The processor is operable to execute the position control algorithm to do the following. The processor receives a boundary command establishing a defined boundary relative to the surface. The processor receives a sensory signal from the sensor wherein the sensory signal includes information related to a movement of the movable structure relative to the defined boundary. The processor determines a position of the movable structure relative to the traveling body, and limits movement of either the ground-engaging mechanism of the traveling body or the actuator of the moveable structure as the traveling body moves along the travel path. This occurs when the position of the movable structure is within an allowable distance from the defined boundary to prevent the moveable structure from moving beyond the defined boundary.

Limiting movement of the movable structure may comprise of a movement envelope. Limiting movement of the movable structure may comprise a yaw angle relative to the traveling body.

According to another aspect, the processor continuously determines the position of the movable structure relative to the defined boundary as the traveling body moves along the travel path.

The boundary command may comprise one or more of the traveling body and the moveable member. The vertical plane may encircle the work machine in concentric circles.

The object detection sensor may comprise of a stereo-imaging apparatus coupled to the work machine, wherein the position control algorithm processes the sensory signal to identify the defined boundary from a stereo-image. The position control algorithm may process the sensory signal to identify a moving object, wherein the sensory signal continuously updates.

The sensor may comprise of a LIDAR imaging apparatus coupled to the work machine, wherein the position control algorithm processes the sensory signal to identify the defined boundary from a point cloud 275.

The processor may further receive an operator input command actuating a movement of the traveling body or the movable structure, and wherein the position control algorithm overrides the operator input command when the movable structure is within the allowable distance from the defined boundary.

Alternatively, the processor may receive an operator input command to actuate movement of the traveling body or the movable structure, wherein the operator input command overrides the position control algorithm when the movable structure is within the allowable distance from the defined boundary.

According to another aspect of the present disclosure, a method of limiting movement of a work machine as the work machine travels, wherein the work machine includes a traveling body coupled to the traveling body, includes receiving a boundary command establishing a defined boundary relative to a ground surface. The method further includes receiving a sensory signal from a sensor wherein the sensory signal includes information related to a movement of the moveable structure relative to the defined boundary; determining a position of the movable structure relative to the traveling body; and limiting movement of either or both of the ground-engaging mechanism coupled to the traveling body or an actuator of the moveable structure as the traveling body moves along a travel path when the position of the moveable structure is within an allowable distance from the defined boundary. This will prevent the moveable structure from moving beyond the defined boundary. Determining the position of the movable structure relative to the defined boundary as the traveling body moves is continuous.

The method may further comprise processing the sensory signal to identify the defined boundary from a stereo-image while the sensory signal is continuously updating. The method may further comprise processing the sensory signal to identify a moving object, wherein the sensory signal continuously updates. The method may also include processing the sensory signal to identify the defined boundary from a point cloud 275.

These and other features will become apparent from the following detailed description and accompanying drawings, wherein various features are shown and described by way of illustration. The present disclosure is capable of other and different configurations and its several details are capable of modification in various other respects, all without departing from the scope of the present disclosure. Accordingly, the detailed description and accompanying drawings are to be regarded as illustrative in nature and not as restrictive or limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of the drawings refers to the accompanying figures in which:

FIG. 1 is a side view of a work machine according to a first embodiment shown as an excavator;

FIG. 2 is a front schematic view of the first embodiment in its environment;

FIG. 3 is a system diagram of the movement limiting elements of the first embodiment shown in FIG. 1;

FIG. 4 is a diagram of a movement envelope of the first embodiment;

FIG. 5 is a schematic top view of the first embodiment in its environment; and

FIG. 6 is a flowchart of a method of limiting movement of a work machine.

Like reference numerals are used to indicate like elements throughout the several figures.

DETAILED DESCRIPTION

The embodiments disclosed in the above drawings and the following detailed description are not intended to be exhaustive or to limit the disclosure to these embodiments. Rather, there are several variations and modifications which may be made without departing from the scope of the present disclosure.

As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).

As used herein, the term “controller” is a computing device including a processor and a memory. The “controller” may be a single device or alternatively multiple devices. The controller 180 may further refer to any hardware, software, firmware, electronic control component, processing logic, processing device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.

The term “processor” is described and shown as a single processor. However, two or more processors can be used according to particular needs, desires, or particular implementations of the controller and the described functionality. The processor may be a component of the controller, a portion of the object detector, or alternatively a part of another device. Generally, the processor can execute instructions and can manipulate data to perform the operations of the controller, including operations using algorithms, methods, functions, processes, flows, and procedures as described in the present disclosure.

FIG. 1 is a side view of an exemplary embodiment of a work machine 100. The work machine 100 is embodied as an excavator including a moveable structure 105 (upper frame) pivotally coupled to a traveling body 110 (undercarriage). The moveable structure 105 can be pivotally coupled on the traveling body 110 by means of a swing pivot, enabling the moveable structure 105 to rotate in a yaw direction 115. The traveling body 110 includes a ground-engaging mechanism 120, including but not limited to, tracks and wheels. The ground-engaging mechanism 120 shown include a pair of ground engaging tracks on opposite sides of the traveling body 110 for moving along a ground surface 125. The moveable structure 105 includes an operator cab 130 (although not required, i.e. this may be done remotely) in which the operator controls the excavator. These controls 132 may include a steering wheel, control levers, control pedals, control buttons, and a graphical user input interface with display which enable operator input commands 135. The moveable structure 105 of the excavator also includes a boom assembly 142 comprising a large boom 140 (first section of the boom assembly 142) adjacent to the operator cab, as well as a dipper stick 145. The large boom 140 is rotatable and creates a vertical arc relative to the operator cab 130 by actuating the large boom actuator (150) (a first actuator). The dipper stick 145 is coupled to the large boom 140 and is pivotable relative to the large boom 140 by means of a dipper stick actuator 155 (a second actuator). Coupled to the end of the dipper stick 145 is an attachment 160 wherein the attachment is pivotable relative to the dipper stick 145 by an attachment hydraulic cylinder 165. In the exemplary embodiment of an excavator, the movable structure 105 includes the operator cab 130, the large boom 140, the dipper stick 145, and the attachment 160.

The work machine 100 also comprises a sensor 170 operable to generate a sensory signal 175. A controller 180, in communication with the sensor 170, includes a processor 185 and a memory 190 having a position control algorithm 195 stored thereon. The processor 185 is operable to execute the position control algorithm 195 to receive a boundary command 200 establishing a defined boundary 205 relative to the ground surface 125; receive the sensory signal 175 from the sensor 170, determine a position of the movable structure 105 relative to the traveling body 110; and limit movement of one of the ground-engaging mechanism 120 of the traveling body 110 or the actuator of moveable structure 105 as the traveling body 110 moves along the travel path 210 when the position of the movable structure 105 is within an allowable distance 215 from the defined boundary 205 to prevent the moveable structure 105 from moving beyond the defined boundary 205.

The processor 185 continuously determines the position of the movable structure 105 relative to the defined boundary 205 as the traveling body 110 moves along the travel path 210. This monitoring may occur by a first determination 222 of the position of the traveling body 110, and a second determination 224 of the of the position of movable structure 105 relative to both the traveling body 110 and the ground surface 125.

The boundary command 200 may comprise of one or more of a pre-planned path 201, a worksite instruction 202, a series of waypoints 203, and an identification of a worked ground surface 204.

In an exemplary embodiment, the series of waypoints 203 may be derived from a bird's eye view image (BEV image), memory, or the work machine “following” another work machine.

As shown in FIG. 3, in one exemplary application, a bucket type attachment 160 digging a straight-line trench with the above-mentioned elements creates a straight travel feature 207. The straight travel feature 207 provides an easy single pedal machine control (i.e. the operator input command 135) where the excavator is limited in movement to move in a straight line (i.e. the defined boundary 205) for activities such as pipe-laying, material handling, installation of underground utilities, and sapling placement, to name a few. Movement of the movable structure 105 relative to the ground surface 125 and limiting movement of movable structure within the allowable distance 215 of the defined boundary 205 advantageously enables to automate or semi-automate movement of the work machine 100 to create the trench. An operation becomes a co-operation (between the operator and work machine 100) in a semi-autonomous mode. As the operator moves the movable structure 105 within the allowable distance 215, the machine can effectively “lock into position” while following the boundary command 200. The system offers little flexibility for the operate to deviate from the travel path 210. In one instance, the defined boundary 205 can be a straight line representing a trench edge or worked ground surface 204 as identified from processing the sensory signal 175 of image of the trench as the work machine follows a boundary command 200. In another instance, the defined boundary 205 may be derived from worksite instructions 202 (e.g. path plan, predetermined endpoint, predetermined length) or a series of waypoints 203. The allowable distance 215 for the movable structure 105 during engagement with the ground surface 125, or more particularly the bucket attachment 160 in the trench building application represents the area where once entered into by the operator's commands, the bucket attachment will remain as the work machine 100 continues to move forward. This is one way of physically integrating worksite instructions with the actual movement of the work machine. In the example shown in FIG. 3, the travel path 210 extends in a fore-aft direction 102 of the traveling body 110. As shown in FIG. 2, at least two degrees of processing occurs which include a first determination 222 of the movable structure 105 relative to the ground surface 125, and a second determination 224 of the traveling body 110 relative to the movable structure 105. An operator input command 135 (e.g. a single pedal in the application disclosed above) may maintain a semi-autonomous mode wherein the operator moves the work machine 100 forward while the processor 185 automatically determines how it should move forward based on the sensory signal 175 by adjusting the ground-engaging mechanism 120, and what adjustments must be made to the moveable structure 105 about the yaw axis 115 (shown in FIG. 5) by adjusting the yaw angle 245.

Limiting movement of the moveable structure 105 may further comprise determining a movement envelope 214. The movement envelope 214 can be located in a plane extending radially from the yaw axis 115 along the plane 232 of the boom assembly 142. FIG. 4 is a line schematic of the movement envelope 214 as it relates to the work machine 100 shown in FIG. 1 (in this case an excavator). The movement envelope 214 is defined by a range of possible movement of a point 225 near the portion of the boom assembly 142 distally located from the operator cab 130. The position of the point 225 is defined by the lengths of the large boom actuator 150 and the dipper stick actuator 155. The perimeter 230 (as designated by the solid black line) of the movement envelope 214 drawn by point 225 is defined by one or more of the large boom actuator 150 and the dipper stick actuators 155 being at a fully extended or retracted position. A perimeter of the large boom hydraulic cylinder movement is shown by a series of first geometric configurations 235 as defined by the mechanical linkage of the boom assembly 142 (shown in FIG. 1). The processor 185 may further be configured to inhibit movement of the point 225 to a plurality of nodes within the movement envelope 214 where there is insufficient actuator capacity for moving a payload and where the position control algorithm 195 has determined the defined boundary 205. In an alternative simplified embodiment, the defined boundary 205 can simply be a vertical plane 250 at or outside of the outermost point of the movement envelopment 214.

Now turning to FIG. 5, a top view of the work machine 100 is shown. As previously discussed, limiting the movement of the moveable structure 105 may further comprise a yaw angle 245 relative to the traveling body 110. More particularly, the yaw angle 245 is the rotation of the moveable structure 105 about the yaw axis 115 from a zero-degree demarcation 260. The zero-degree demarcation 260 may further be defined as the default alignment of the movable structure 105 relative to the traveling body 110. In the embodiment of the excavator shown, the zero demarcation 260 extends in the fore-aft direction 102 of the traveling body 110 (i.e. between each ground-engaging mechanism 120). That is, the boom assembly 142, which is a portion of the moveable structure 105 in the example shown of an excavator, may be oriented in the fore-aft direction 102 at the zero demarcation 260. The zero-degree demarcation 260 and the yaw axis 115 may depend on the type of work machine 100 and can be assigned arbitrarily.

In one embodiment, the sensor 170 comprises a stereo-imaging apparatus 265 coupled to the work machine, wherein the position control algorithm 195 processes the sensory signal 175 to identify the defined boundary 205 from a stereo-image. The position control algorithm 195 further processes the sensory signal 175 to identify a moving object as the sensory signal 175 continuously updates.

In another embodiment, the sensor 170 comprises a LIDAR imaging apparatus 270 coupled to the work machine, wherein the position control algorithm 195 processes the sensory signal 175 to identify the defined boundary 205 from a point cloud 275. Another advantage of using this system includes maintaining grade control of an attachment 160 (e.g. in backhoe loaders) as the work machine 100 carves the ground surface 125.

In another embodiment, the processor 185 receives an operator input command 135 actuating movement of one or more of the traveling body 110 and the movable structure 105. The position control algorithm 195 may override the operator input command 135 when the movable structure 105 is within the allowable distance 215 from the defined boundary 205, thereby placing the work machine in an automatic mode.

Alternatively, the operator input command 135 may override the position control algorithm 195 when the movable structure 105 is within the allowable distance 215 from the defined boundary 205 in the event of pausing work for the day.

FIG. 6 is a method 600 of limiting movement of a work machine 100 (as previously described), as the work machine 100 travels wherein the work machine 100 includes a traveling body 110 with a moveable structure 105 coupled on the traveling body 110. The controller 180 comprises a processor 185 and a memory 190, wherein the processor uses a position control algorithm 195 to perform the following steps. In a first step 610, the method 600 comprises the processor 185 receiving a boundary command 200. In a next step 620, the processor 185 receives a sensory signal 175 from a sensor 170 wherein the sensory signal 175 includes information related to movement of the moveable structure 105 relative to the ground surface 125. Step 620 may occur subsequently, simultaneously, or prior to step 610. In step 630, the processor 185 may then determine a position of the movable structure 105 relative to the traveling body 110. In step 640, determine the defined boundary 205.

Finally, in step 650, the processor 185 limits movement according to one or more of steps 660, 670, and 680. Step 650 comprises limiting movement of a ground-engaging mechanism 120 coupled to the traveling body 110. This may include altering track speeds to alter a direction of movement. Step 670 comprises limiting movement of an actuator (150, 155, 165) controlling the boom assembly 142 within a movement envelope 214. Step 680 comprises limiting movement of the moveable structure 105 with respect to the angular orientation (i.e. yaw angle 245) of the movable structure 105 to the traveling body 110 as the traveling body moves along the travel path. Each of these occurs when the position of the movable structure 105 is within the allowable distance 215 from the defined boundary 205 to prevent the moveable structure 105 from moving beyond the defined boundary 205. When receiving the sensory signal 175, the method 600 may include processing the sensory signal 175 to identify the defined boundary 205 from a stereo-image. The method 600 may include the processing of the sensory signal 175 to identify a moving object while the sensory signal 175 continuously updating. The method 600 also comprise processing the sensory signal 175 to identify the defined boundary from a point cloud.

In one embodiment, step 690 of the method 600 may comprise receiving an operator input command 135 for actuating movement of the traveling body 110 or the movable structure 105, and overriding the operator input command 135 when the movable structure 105 is within the allowable distance 215 from the defined boundary 205.

In another embodiment, step 695 of the method 600 the method may comprise receiving an operator input command 135 for actuating movement of the traveling body 110 or the movable structure 105; and overriding a movement limit when the movable structure 105 is within the allowable distance 215 from the defined boundary 205.

The terminology used herein is for the purpose of describing particular embodiments or implementations and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the any use of the terms “has,” “have,” “having,” “include,” “includes,” “including,” “comprise,” “comprises,” “comprising,” or the like, in this specification, identifies the presence of stated features, integers, steps, operations, elements, and/or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The references “A” and “B” used with reference numerals herein are merely for clarification when describing multiple implementations of an apparatus.

One or more of the steps or operations in any of the methods, processes, or systems discussed herein may be omitted, repeated, or re-ordered and are within the scope of the present disclosure.

While the above describes example embodiments of the present disclosure, these descriptions should not be viewed in a restrictive or limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the appended claims. 

What is claimed is:
 1. A work machine comprising: a traveling body having a ground-engaging mechanism controllable to move the traveling body along a travel path relative to a ground surface; a moveable structure coupled to the traveling body and having an actuator controllable to move the moveable structure relative to the traveling body; a sensor operable to generate a sensory signal; a controller in communication with the sensor, the controller including a processor and a memory having a position control algorithm stored thereon, wherein the processor is operable to execute the position control algorithm to: receive a boundary command establishing a defined boundary relative to the ground surface; receive the sensory signal from the sensor, the sensory signal including information related to a movement of the movable structure relative to the defined boundary; determine a position of the movable structure relative to the traveling body; and limit movement of one of the ground-engaging mechanism of the traveling body or the actuator of the moveable structure as the traveling body moves along the travel path when the position of the movable structure is within an allowable distance from the defined boundary to prevent the moveable structure from moving beyond the defined boundary.
 2. The work machine of claim 1, wherein the processor continuously determines the position of the movable structure relative to the defined boundary as the traveling body moves along the travel path.
 3. The work machine of claim 1, wherein the boundary command comprises one or more of a pre-planned path, a worksite instruction, a series of waypoints, and an identification of a worked ground surface.
 4. The work machine of claim 1, wherein limiting the movement of the movable structure comprises a movement envelope.
 5. The work machine of claim 1, wherein limiting the movement of the movable structure comprises a yaw angle relative to the traveling body.
 6. The work machine of claim 1, wherein the sensor comprises a stereo-imaging apparatus coupled to the work machine, wherein the position control algorithm processes the sensory signal to identify the defined boundary from a stereo-image.
 7. The work machine of claim 6, wherein the position control algorithm processes the sensory signal to identify a moving object, the sensory signal continuously updating.
 8. The work machine of claim 1, wherein the sensor comprises a LIDAR imaging apparatus coupled to the work machine, wherein the position control algorithm processes the sensory signal to identify the defined boundary from a point cloud.
 9. The work machine of claim 1, wherein the processor receives an operator input command actuating a movement of the traveling body or the movable structure; and wherein the position control algorithm overriding the operator input command when the movable structure is within the allowable distance from the defined boundary.
 10. The work machine of claim 1, wherein the processor receives an operator input command actuating movement of the traveling body or the movable structure, the operator input command overriding the position control algorithm when the movable structure is within the allowable distance from the defined boundary.
 11. A method of limiting a movement of a work machine as the work machine travels, wherein the work machine includes a traveling body with a moveable structure couple to the traveling body, the method comprising: receiving a boundary command establishing a defined boundary relative to a ground surface; receiving a sensory signal from a sensor, the sensory signal including information related to a movement of the moveable structure relative to the defined boundary; determining a position of the movable structure relative to the traveling body; and limiting movement of one of a ground-engaging mechanism coupled to the traveling body or an actuator of the moveable structure as the traveling body moves along a travel path when the position of the movable structure is within an allowable distance from the defined boundary to prevent the moveable structure from moving beyond the defined boundary.
 12. The method of claim 11, wherein determining the position of the movable structure relative to the defined boundary as the traveling body moves is continuous.
 13. The method of claim 11, wherein the boundary command comprises one or more of a pre-planned path, a worksite instruction, a series of waypoints, and an identification of a worked ground surface.
 14. The method of claim 11, wherein limiting the movement of the movable structure comprises a movement envelope of the traveling body.
 15. The method of claim 11, wherein limiting the movement of the movable structure comprises a yaw angle relative to the traveling body.
 16. The method of claim 11, further comprising: processing the sensory signal to identify the defined boundary from a stereo-image, the sensory signal continuously updating.
 17. The method of claim 16, further comprising: processing the sensory signal to identify a moving object, the sensory signal continuously updating.
 18. The method of claim 11, further comprising: processing the sensory signal to identify the defined boundary from a point cloud.
 19. The method of claim 11, further comprising: receiving an operator input command for actuating the movement of the traveling body or the movable structure; and overriding the operator input command when the movable structure is within the allowable distance from the defined boundary.
 20. The method of claim 11, further comprising: receiving an operator input command for actuating movement of the traveling body or the movable structure; and overriding a movement limit when the movable structure is within the allowable distance from the defined boundary. 